• Polymer(Korea)
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• v.27 no.4
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• pp.323-329
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• 2003

Stretchable Polypyrrole films using functionalized doping agent, di(2-ethylhexyl) sulfosuccinate sodium salt (NaDEHS), were synthesized by chemical and electrochemical method. Chemically and electrochemically Prepared Polypyrrole films were stretch-oriented (L/L$\_$0/＝ 1.0 ∼ 2.5) by zone drawing method and the electrical conductivities were measured. As the draw ratio was increased, the electrical conductivities were increased. This result was confirmed by the increase in crystallinity through the increase in draw ratio. The temperature dependence of electrical conductivity showed that 3D-variable range hopping model (L/L$\_$0/ ＝ 1.0∼2.0) and ID-VRH model (L/L$\_$0/ ＝ 2.5) gave the best fit to the data for stretched Ppy-DEHS films.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.137-142
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• 2008

Growth and survival rates dependent on the density of a pen sell, Atrina pectinata were measured from Duekryang bay in Korea. Annual water temperature and salinity of the study area were ranged from 14.5 to $28.0^{\circ}C$ and from 27.98 to 31.89 psu, respectively. The pH, DO, COD, DIN, Chl-a and SPM in the study area ranged from 7.78-8.35 mg/L, 7.07-7.90 mg/L, 1.20-1.70 mg/L, 2.88-6.02 mg/L, 0.20-0.79 mg/L and 10.8-21.4 mg/L. The IL, COD and AVS in sediments ranged from 4.0-4.6%, 7.28-10.76 mg/L and 0.03-0.05 mg/L respectively. The daily growth rate of shell height and total weight were 0.27%, 0.33%(5 indiv./$m^2$), 0.26, 0.29%(10 indiv./$m^2$) and 0.21, 0.20%(35 indiv./$m^2$). The survival rate also decreased along the density gradient; highest at the lowest density of 5 indiv./$m^2$ and lowest at the maximum density of 35 indiv./$m^2$.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.461-468
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• 2018

A highly sensitive, selective and rapid method for the determination of lead based on the reaction of lead (II) with 5-(4'-chlorophenylazo)-6-hydroxypyrimidine-2,4-dione (CPAHPD) and the solid phase extraction of the Pb(II)-CPAHPD complex with Amberlite XAD-2000 was developed, in the presence of pH 5.6 buffer solution and Triton X-114 medium. CPAHPD reacts with lead to form a violet complex with a molar ratio of 2:1 (CPAHPD to lead). This complex was enriched by the solid phase extraction with Amberlite XAD-2000. An enrichment factor of 500 was obtained by elution of the complex from the resin with a minimal amount of isopentyl alcohol(0.2 mL). In isopentyl alcohol medium,the molar absorptivity of the complex is $1.13{\times}10^6L\;mol^{-1}cm^{-1}$ at 647 nm. Beer's law is obeyed in the range of $5.0-160ng\;mL^{-1}$ in the measured solution. The relative standard deviation for 10 replicate samples of $50ng\;mL^{-1}$ level is 1.26%. The detection and quantification limits reaches 1.5 and $4.7ng\;mL^{-1}$ in the original samples. The presented procedure was successfully applied for determination of lead content in real samples such as vegetables, waters, biological and soil samples with satisfactory results.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.231-240
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• 2016

Techniques were developed for holding and conditioning of Pacific oysters, Crassostrea gigas, in a closed recirculating system. Experimental adults were used 500 oysters ( x two system, total 1,000 oysters) which were collected in $20^{th}$ March 2016 from long-line aquaculture farm at the south coast of Korea. During conditioning periods concentrated live microalgae as Isochrysis sp. $15{\times}10^7cells/mL$, Tetraselmis sp. $2{\times}10^7cells/mL$ and Pheaodactylum sp. $18{\times}10^7cells/mL$ were added 5 L every day, respectively which micro algae were functioned as diets and biological filter. Over all experimental periods total water exchange rate was 21.3% (daily 0.5%). Over 42 days conditioning, female and male oysters were maturated 90.9% and 94.4%, respectively. Survival rate was 98.7%. Mean shell hight (8.3 mm), total wet weight (19.2 g), meat wet weight (5.0 g) and shell wet weight (13.6 g) were significantly increased (P < 0.05). Water quality parameters including the water temperature ($22.1{\pm}0.4^{\circ}C$), salinity ($24.9{\pm}04$), dissolved oxygen (5.1-7.9 mg/L) and pH ($7.93{\pm}0.15$) were kept stable. Concentration of dissolved inorganic nutrient as ammonia (1.96-0.35 mg/L), nitrite (0.03-0.16 mg/L), nitrate (1.34-0.47 mg/L), DIP (0.42-0.03 mg/L) and silicate (3.83-0.00 mg/L) were significantly decreased throughout experiment except nitrite which was increased (P < 0.05), but nitrogenous components stayed below toxic levels (ammonia 0.0-5.5 mg/L, nitrite 0.0-460.0 mg/L) which indicated that closed recirculation system with microalgae based bio-filter could supply sufficiently environment condition to holding and conditioning of oyster.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.495-508
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• 2019

We measured the concentrations of natural radionuclides (uranium and radon) and major elements in groundwater collected from forty wells located in Wonju area to investigate the hydrochemistry and the occurrence of these radionuclides. The range of electrical conductivity (EC) value in the study area was 73~400 μS/cm. In addition to the increase of EC value, the content of cations and anions also tends to increase. Uranium concentrations ranged from 0.06~50.5 ㎍/L (median value, 1.55 ㎍/L) and radon concentrations ranged from 67~8,410 pCi/L (median value, 1,915 pCi/L). Uranium concentrations in 3 well, 7.5% of the samples, exceeded 30 ㎍/L, the maximum contaminant level (MCL) proposed by the US Environmental Protection Agency (EPA), based on the chemical toxicity of uranium. Radon concentrations in 9 wells, 22.5% of the samples, and 1 well, 2.2% of the samples, exceeded 4,000 pCi/L (AMCL of the US EPA) and 8,100 pCi/L (Finland's guideline level), respectively. Concentrations of uranium and radon related to geology of the study area showd the highest values in groundwater of the biotite granite area. Uranium and radon contents in the groundwater are comparatively low compared to those in other countries with similar geological settings. It is likely that the measured value was lower than the actual content due to the inflow of shallow groundwater by the lack of casing and grouting.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.239-243
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• 1985

The growth characteristics of Candida sp. JY-5 were examined on ethanol, acetic acid, or acetaldehyde as sole source of carbon by batch culture. The specific growth rates ($\mu$) of this strain on an ethanol during tile exponential period were changed depending upon the initial concentrations at above 0.5 g/l, but not in the proportion. The highest $\mu$ value was 0.291 hr$^{-1}$ and the maximum growth yield was 61.2％ at the concentration of 10 g/l. The $\mu$ values on an acetic acid substrate were constant regardless of the initial concentrations presenting 0.106 hr$^{-1}$ in the highest value. The maximum growth yield was shown as 46.8％ at the initial concentration of 10 g/l. The $\mu$ value on an acetaldehyde during the exponential period was 0.063 hr$^{-1}$ and the maximum growth yield was 44.9％ at the initial acetaldehyde concentration of 0.2 g/l.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.985-989
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• 2010

This experiment was conducted to clarify the effects of 1-methylcyclopropene (1-MCP) on vase life of cut 'Blue Magic' iris. Pretreatment for 4 h with concentrations of 500 nL and 1000 nL 1-MCP, an inhibitor of ethylene action, inhibited the wilting and inrolling response of cut iris. The vase life of iris flowers of 500 nL or 1000 nL 1-MCP treatment was prolonged to 0.5 day compared to those held in distilled water (control). Vase life of iris showed no significant difference between $3{\mu}L{\cdot}L^{-1}$ ethylene exposure after 1-MCP treatment and control. 1-MCP treatment inhibited inrolling and increased fresh weight, water uptake, and water balance. The increase of fresh weight was high in 500 nL 1-MCP treatment and water uptake was increased by 1000 nL 1-MCP. Especially, iris flower without 1-MCP treatment dramatically decreased the water uptake as compared to the control for four or five days. Water balance of iris flowers held in water was changed to minus value faster than those with pretreatment of 1-MCP.

• Food Science and Preservation
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• v.9 no.3
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• pp.351-355
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• 2002

The purpose of this study was to investigate the nitrite scavenging, eletron donating activity and antioxidant activity of wood vinegar on soybean oil. Wood vinegar was added to soybean oil in the quantities of 0.5, 1 and 5%. Nitrite scavenging effect of all concentrations diminished at higher pH, while in the case of pH 1.2, it showed a nitrite scavenging effect of more than 80% at concentration above of 100 ㎕/mL. The electron donating activity was about 80% at concentration above of 50 ㎕/mL. Soybean oil without the addition of wood vinegar was used as a control. The oxidation of these samples was determined by measuring the peroxide value(POV), thiobarbituric acid(TBA) value and acid value(AV). When wood vinegar was added 1 and 5%, the peroxide value wag lower than both the control and 0.1% BHT. TBA value were in the 5% wood vinegar tallowed by 1% wood vinegar, 0.1% BHT, 0.5% wood vinegar and the control, respectively. The results showed that the acid values were lowest in 5% wood vinegar, followed by the 0.1% BHT, 1% wood vinegar, 0.5% wood vinegar and finally the control.

• Korean Journal of Plant Resources
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• v.35 no.5
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• pp.574-585
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• 2022

This study was conducted to quantify chlorogenic acid content and evaluate biological activity, such as antioxidant, antibacterial, anti-inflammatory, and digestive enzyme activity of Aralia elata ethanol extract (AEE). The SC₅₀ of DPPH and ABTS radical scavenging activities of AEE were 4.79±0.05 mg/mL, 5.79±0.05 mg/mL; total polyphenol and total flavonoid contents were 170.0±1.8 mgGAE/g, 105.5±4.1 mgQE/g, respectively. Nitric oxide (NO) was increased in RAW 264.7 cells and Caco-2 cells with treatment of LPS, and production of NO was inhibited by AEE in a concentration-dependent manner. Production of NO was reduced by 60.0±1.1% in RAW 264.7 cells and 50.7±2.8% in Caco-2 cells at of AEE. Similarly, the production of inflammatory cytokines (TNF-α, IL-1β and IL-6) was inhibited in a concentration dependent manner. Antibacterial activity increased as the dose concentration of AEE increased, and the MIC was 75 mg/mL for L. monocytogenes, and 100 mg/mL for S. typhimurium and H. pylori. In addition, amylase and protease enzyme activity was observed in AEE and increased enzyme activity was observed according to the concentration of the extract. AEE contained 7.06±0.01 mg/g of chlorogenic acid. As a result of the experiment, it is judged that it can be used as basic data for the development of health food using Aralia elata.

• Journal of Chest Surgery
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• v.34 no.6
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• pp.454-464
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• 2001

Background: It has been recognized that systemic inflammatory reaction and oxygen free radical formed by activated leukocyte in the procedure of cardiopulmonary bypass(CPB) frequently produce postoperative cardiac and pulmonary dysfunction. The purpose of this study was to evaluate the efficacy of leukocyte-depleting filters in the cardiopulmonary bypass circuit for patients undergoing open heart surgery(OHS). Material and method: The study involved 15 patients who underwent OHS with a Leukoguard-6 leukocyte filter placed in the arterial limbs of the bypass circuit(filter group, n=15) and 15 patients who did not have the filter(control group, n=15). We analyzed the differences between the groups in intraoperative changes of peripheral blood leukocyte and platelet counts, pre- and postbypass changes of malondialdehyde(MDA), troponin-T(TnT), 5'-nucleotidase(5'-NT) in coronary sinus blood, spontaneous recovery rate of heart beat after CPB, pre-and postoperative cardiac index(Cl) and pulmonary vascular resistance(PVR), and the amounts of postoperative bleeding and sternal wound complication. Result: During CPB, total leukocyte count of the filter group(9,567$\pm$ 842/㎣) was significantly less than that of the control group(13,573+1,167/㎣) (p<0.01), but there was no significant difference in platelet count between the groups. Postoperative levels of MDA(3.78+0.32 $\mu$mol/L vs 5.86+0.65 $\mu$mo1/L, p<0.01), TnT(0.40$\pm$0.04 ng/mL vs 0.59$\pm$0.08 ng/mL, p<0.05) and 5'-NT(3.88$\pm$0.61 U/L vs 5.80$\pm$0.90 U/L, p<0.05) were all significantly lower in the filter group than the control group. Postoperative Cl was higher in the filter group than the control group(3.26$\pm$0.18 L/$m^2$min vs 2.75$\pm$0.17 L/$m^2$/min, p=0.05). PVR of the filter group was lower than that of the control group(65.87$\pm$7.59 dyne/sec/cm$^{5}$ vs 110.80+12.22 dyne/sec/cm$^{5}$ , p<0.01). Spontaneous recovery rate of heart beat in the filter group was higher than that in the control group(12 patients vs 8 patients, p<0.05). Postoperative wound infection occurred in one case in the filter group and 4 case in the control group(p<0.05). Postoperative 24 hour blood loss of the filter group was more than that of the control group (614$\pm$107 mL vs 380+71 mL, p=0.05).